In conventional orthodontic treatments, two methods of treatment are primarily used. The first technique is known as the edgewise technique, which consists of applying moving force to the tooth by the use of a bracket having a rectangularly sectioned arch wire receiving slot with an arch wire received therein. The tooth is moved by the application of angular torque to the bracket by the square sectioned arch wire. This torque is transferred to the underlying tooth, attached to the bracket, which then moves in the desired direction. A variation on the edgewise technique is the Straight wire technique. In the straight wire technique, the torque and angulation are preadjusted in the bracket.
The second technique uses a lighter wire and is known as the Begg light wire technique. This technique is characterized by the application of a light, round sectioned arch wire, the force being applied to the tooth bracket by a different form of attachment of the light wire to the bracket. The result is similar to that of the rectangularly sectioned arch wire in that the energy stored in the wire by spring means is transferred to the tooth over time. It is very useful to have the versatility of a combination bracket that allows the use of either technique singly or both techniques simultaneously.
The problem associated with the prior art combination orthodontic brackets for use with the above discussed techniques is the bulkiness of the bracket. An example of a prior art tooth bracket is shown in FIGS. 1 and 2. The bracket 10 comprises a backing member 12 (for attachment to either a tooth band or the tooth directly), a body member 11 which has a horizontal slot 16 and vertical slot 14 located therein.
FIG. 2 illustrates the bracket of FIG. 1 using the light wire corrective technique. Conventional long pin 15 is inserted into the vertically oriented slot to wedge against and hold light wire 40 against the backing member of the bracket.
The bracket of FIGS. 1 and 2 is characterized by the location of the horizontal slot 16 in non-intersecting relation to vertical slot 14. This bracket configuration necessarily results in a relatively thicker, bulky, bracket which, because of its thickness, places the square arch wire a comparatively large distance from the surface of the tooth and impairs the performance thereof. Additionally, the increased bulk results in decreased wearer comfort due to the surrounding cheek tissue resiliently pressing against the protruding brackets and wires.
Examples of bulky prior art orthodontic bracket devices are disclosed in U.S. Pat. Nos. 4,496,318, 4,427,381, 4,227,876 and 3,163,933. Universally however, the prior art brackets are needlessly bulky and are, therefore, uncomfortable to the wearer and further provide inferior precision for the orthodontist.